In T 951/97 (OJ 1998, 440), although document D4 had been mentioned in the European search report, it had not been cited at any stage in the examination procedure prior to the oral proceedings. The board found that the half an hour adjournment of the oral proceedings had been too short a period for an adequate analysis of the complex text of D4. As D4 was essential to the finding of the examining division in relation to inventive step, the decision was based on evidence on which the applicants had not had a sufficient opportunity to present their comments as required by Art. 113(1) EPC 1973 (see also T 492/03).
In T 783/89 the opposition division had proposed a new version of the main claim at the start of the oral proceedings, giving the opponents ten minutes to consider it. The board ruled that this had taken the opponents by surprise, and that the time given had not been sufficient to study the allowability of the amendments.
In T 2235/12 the examining division had introduced, two days before the oral proceedings, two additional documents and a new objection into the procedure. The appellant's request for a postponement of the oral proceedings was rejected, and the appellant did not attend the oral proceedings. The board held that the new objection was not related to the points indicated in the summons and that the appellant should have been given an adequate opportunity to react to the new objection. Attending the oral proceedings would not have changed the fact that the timeframe was too short for the representative to get instructions from the client and to prepare for oral proceedings with a new focus. The board concluded that rejecting the appellant's request for a postponement of the oral proceedings infringed the appellant's right to be heard.
In T 75/10 the board saw no reason to overturn the opposition division's admission of late-filed documents that appeared highly relevant for novelty. However, the board considered that the opposition division should have granted the patentee's request for postponement of the oral proceedings, after deciding to admit these. The board stated that there was an essential difference between a prima facie assessment of the possible relevance and publication date of a late-filed document for deciding upon its admission into the proceedings and the full in-depth assessment of novelty vis-à-vis such a document, which required determining whether the document was made available to the public before the effective filing date. In the case at hand, the documents were generated from an archive different from the databases commonly used for a prior-art search. Therefore, the difficulties encountered by the patentee at the oral proceedings when trying to verify the origins of the late-filed documents were plausible.
In T 763/15 the board held that the appellant's right to be heard had been violated by the opposition division – it could not see any indication that the appellant had been allowed to argue during the oral proceedings on the issue of admissibility of auxiliary request 2. In the opposition proceedings the chairman, after commenting on the amendment made to claim 1 of auxiliary request 2, immediately announced "that AUX2 is not admitted in the proceedings". A decision taken and pronounced by the opposition division cannot be challenged any more in the same proceedings. Therefore, the board considered it to be irrelevant that "The Patentee did not react on this decision not to admit AUX2 in the proceedings", as recited in the minutes.